Well developer



Dec. l, 1959 R. l.. CLARK 2,915,128

WELL DEVELOPER Filed May 9, 195.8

Arrakis/y United States Patent() WELL DEVELOPER Robert L. Clark,Indianapolis, Ind.

Application May 9, 1958, Serial No. 734,154

'3 Claims. (Cl. 166--177) This invention relates to a tool fordeveloping wells, primarily water wells. The making of a well consistsof more than simply drilling a hole in the earth down into the watervein. When the well has been initially drilled to the desired depth, andthe drill hole has been supplied with casing, there remains the job ofwhat is well known as developing the well.

This developing of the well consists in forming, in effect, a waterreservoir about the lower end of the casing or end of the drill hole byremoving tine particles vsuch as sand and clay so that, in a gravelwell, there remains about the lower end of the drill hole a Zone ofwashed out gravel, from between the stones and pebbles of which, thesand and clay is removed to leave interstices iilled with water so thatthere may always be a considerable volume of water about the lower endof the well, this reservoir being iilled by inilow from the general veinof water.

Unless the well is developed in this manner by removing such finematerial, the well will not operate satisfactorily since the screen atthe lower end which is usually provided will become clogged with thefine particles to the extent that water may not be lifted in the casing.Also in the event that such sand does break loose to provide openingsinto the screen, that sand will continue to be pumped up to thedetriment of pumps themselves, cutting away valve seats or where jetsare used cutting away the Venturi throat, and in general producing veryundesirable results.

My invention provides a tool utilized solely for the purpose ofdeveloping a well as above indicated. The tool is employed to not onlysurge the water in the casing particularly at the bottom thereof toagitate and break loose the ne particles in the coarser gravel or infissures of rock where the lower end of the well penetrates rock. Notonly is the tool employed for surging, but it also is employed to liftthe sand up out of the casing by maintaining it in such an agitatedstate that it will remain in suspension rather than precipitate out inthe lifting action.

In addition to the foregoing purposes, the tool is particularlyconceived to avoid sand locks; to permit easy insertion into the casing;easy removal from the casing; and permitting an easy fabrication of thetool with low upkeep in the highly abrasive eld.

These and many other objects and advantages of the invention will becomeapparent to those versed in the art of well drilling, and from thefollowing description of one particular form of the tool which isillustrated in the accompanying drawing, in which:

Fig. l is a view in central vertical section through a constructionembodying the invention as contained within a well casing; and

Fig. 2 is a like view in longitudinal central section of the devicewherein the tool has been operated to an upper end of a lift action. v

Referring to the drawing, the usual and well known casing indicated bythe numeral is provided in the drill hole, and there may be or may notbe a screen 11 xed at the lower end of the casing 10, depending uponwhether ice or not the well is drilled into gravel or stops at an uppersurface of rock or even penetrates the rock. The screen 11 will benormally used in a gravel well.

An upper valve -cage 12 has an upwardly extending, conically formed stem13 externally threaded to receive thereover a collar 14 attached to theusual well drillers cable (not shown). This forms what is termed in thetrade as an API tool joint.

The cage 12 has an external diameter less than the internal diameter ofthe casing 10, and is provided with a plurality of windows 15therethrough spaced circumferentially around the cage. A valve disc 16made out of any suitable pliable elastic material such as rubber iscarried in the cage 12, by means of an under-weighted body 17 from whicha stem 18 extends upwardly through the disc 16, and through an upperconfining plate 19 to receive a nut 20 thereon screw-threadedly as ameans for disc 16 bears.

The external upper end portion of the nipple 21 is threaded not only toenter the cage 12, but also to receive. a lock nut 22 to abut the lowerend of the cage 12 so that the cage 12 does not become accidentallyloosened or displaced from the. nipple 21.

The nipple 21 is provided with/,a shoulder 23 on which is seated anannular packing ring 24 having an external diameter slightly less thanthe internal diameter of the casing 10 so that a clearance normally maybe had between the external, circumferential surface of the ring 24 andthe inner side of the casing 10. In'a four inch casing, this clearancewould be approximately one sixteenth of an inch. The spacing of theshoulder 23 from the lock nut 22 is made to be such that there is aslight clearance between the topside of the packing ring 24 and theunderside of the nut 22. That is, the packing ring 24 is free to travelwithin the limited confines of the shoulder.23 and the underside of nut22. The ring 24 will expand into a compressive sliding iit with thecasing under pressure exerted by a column of water thereabove.

Holes 25 are drilled throughy the nipple 21 at the upper level of thepacking ring 24. These holes are centered in a common plane around thenipple herein shown as immediately below the lock nut 22. Preferably thenipple 21 is milled as at 26 to provide a cavity surrounding the outerends of these holes 25immediately at the top end of the packing ring 24.y r1`he shoulder 23 is on the topside of a land 27( of the nipple 21which approaches the inner side of the casing 10 with a free slidingfit, this particular rit not intended to be a sealing t since thepacking ring -24 performs the sealing function. y

An outersleeve pipe 28 enters by its upper end screwthreadedly into thelower end of the nipple 21, providing a smooth passageway through the.nipple 21' from the' valve disc 16 and into the sleeve pipe 28. Thissleeve.l

,pipe 2S is provided with a number of holes 29 therethrough immediatelybelow the lower end of the nipple 21. Other holes 30 are providedthrough the sleevev pipe 28 intermediate its ends.

The lower end of the sleeve pipe 28 carries a head 31 which has aportion extending inwardly to form an internal, upwardly presentedannular shoulder 32. TheI externaldiameter of the sleeve pipe 28 isconsiderably", less than is the internal diameter of the casing 10.

An inner tube 33, open at both ends, has an upper h`ead 34 as acontinuation of the tube 33, and provides an external surface in slidingContact with the internal side of the outer sleeve pipe 28. The outerdiameter of the inner sleeve tube i33 is less than the internal diameterof the outer sleeve pipe 28 so that there is an annular clearancetherearound. The head 34 will strike the shoulder 32 if the inner sleevetube 33 is allowed to drop downwardly within the pipe 28, and thusarrest further longitudinal travel downwardly of the tube. Thislowermost travel is indicated in Fig. 2, whereas in Fig. l, the tube 33is at approximately its upper limit of travel Vrelative to thesurrounding sleeve pipe 28. For purposes which will hereinafter bedescribed, a bolt 35 may be passed through holes 30 in the pipe 28, andholes 36 provided through the tube 33 at various positions along itslength. The bolt 3S may be secured in place by a nut 37. In this manner,relative travel between the tube 33 and its surrounding pipe 28 isprevented.

The tube 33 has screw-threadedly engaged on its lower end a lower valvecage 38. This lower valve cage 38- serves as a stop, when the bolt '3:3is removed, limiting the upper travel of the tube 33 within the pipe 28.

This cage 38 is a duplicate of the cage 12, and carries therewithin thevalve disc 39 which seats on the at end of a nipple 40 screw-threadedlyengaging through the lower end of the cage 38. Above the disc 39 andthrough the side wall of the cage 38 are a plurality of entry and exitwindows 41. The external diameter of the cage 38 is less than theinternal diameter of the casing 101 so that there may be ow of water orother fluid encountered in the well therearound. A collar or lock nut 42also screw-threadedly carried on the nipple 40 abuts the lower end ofthe cage 38 so as to secure it lixedly on the nipple 40. A packing ring43 surrounds the nipple 4i) immediately below the collar 42, and betweenthe packing ring 43 and the underside of the col. lar 42 are a pluralityof holes 44 affording passageways over the top of the packing ring 43and into the inside of the nipple 40.

A collar 45 carries an annular, inwardly extending head 46 which bearsupon an outwardly and annularly extending foot 47 on the lower end ofthe nipple 4l). The collar 45 extends below the lower end of the nipple48 and screw-threadedly engages a collar 48. The collars 45 and 48 haveexternal diameters less than that of the internal diameter of the casing10. The lower end of the collar 48 may be shaped as may be desireddepending upon what is encountered at the lower end of the casing. Wherethere is a screen 11 at the lower end of the casing 10, the collar 48may be shaped to swage that screen into intimate contact with thecasing. On the other hand, some installations require a lead packingwhich also may be swaged into position by the lower end of the collar48. In wells in rock, the lower end of the collar 48 may even rest onthe rock itself. Therefore the particular shape of the lower end of thecollar 48 may vary all as is well known to those versed in the art, andthis shape does not enter into the present invention per se. The packingring 43 has freedom to travel slightly longitudinally of the nipple 40between the collar 42 and the collar 45. This packing 43 is made out ofa suitable resilient and elastic material such as rubber, so that it mayexpand and form a tight seal against the inside of the casing 10.

A suction or tail pipe 49 is screw-threadedly engaged in the lower endof the collar 48 where a screen 11 is employed, and this tail pipe 49will extend well down within the screen 11. The tail pipe 49 isperforated by holes 50 therearound and throughout its length.

Operation After the drilling operation has been completed and the casingdriven down to its nal position, the construction above described islowered into the casing 10 Vanimas by being carried by the member 14. Itis lowered inthe casing 10 until the tail pipe 49 is entered within thescreen 11, preferably with the collar 48 resting on the top of thescreen, and the packing 43 is in compressive contact with the inside ofthe casing 1t). However, before lowering the tool into the casing 18,the bolt 35 has been removed. The member 14 is then reciprocated in theusual manner vertically within the casing l0, so that the upper valvecage 12 is reciprocated likewise while the lower cage 38 remainsstationary. The reciprocation of the valve cage 12 is limited in extentby the degree of permissible travely of the pipe 28 along the thenstationary inner tube 33 without violently striking the lower head 31against the head 34. In this reciproeating action, the disc 16 liftsfrom the end of the nipple 2l as the water surges upwardly from the pipe28, and the disc 39 of the lower valve is iirmly seated. The uplift ofthe valve cage l2 then carries the liquid up-` wardly in the casing 10whereupon the disc 39 will lift and' allow additional liquid to flow infrom through the tail pipe 49 primarily. In this manner, a simple pumpis maintained with the pipe 28 reciprocating longitudinally of the tube33. This will tend to carry upwardly under the inflow of water throughthe screen 11 sand and clay particles even in colloidal suspension.

However this simple pumping action is not normally sulicient to developthe well properly, and after the initial pumping, the entire assemblymay be lifted with the member 14 and the bolt 35 installed tointerconnect the outer sleeve pipe 28 and the inner sleeve tube 33 sothat they cannot travel one relative to the other. Then the device sofixed is lowered again into the casing 10, and reciprocated upwardly anddownwardly so as to set up an extreme agitation and surging action ofthe water below the device, the packing 43 in this instance travelingwith the device up and down within the casing. This surging andagitating of the water within the casing 10 -will tend to break looseany of the sand and clay particles which will have tended to haveclogged the openings in the screen l1, and also, most importantly, willhave forced water outwardly in streams through the screen 11 to disturband release the sand particles from their engagement with the largerpebbles or rocks in the zone of gravel about the screen. This breaklooseof the sand and clay particles and even limestone particles is necessaryin order to develop the reservoir as above indicated. After a period ofthis surging action, the device is then pulled from the casing again,and the bolt 35 is removed, so that the pumping action can then berestored. In this pumping action, there is set up considerable agitationby reason of the construction of the diametrically spaced apart tube andpipe with the holes extending through their sides throughout theirlengths; `In other words, not all of the liquid is lifted on an up.-stroke of the upper cage 12, but quite a bit of it will surge outwardlythrough the holes in one part of the stroke, and then will enter againinto the pipe and tube on another cycle of the stroke so that the liuidis continually being agitated at all times aiding in preventingprecipitation of the foreign particles in the water. The collection orsedimentation of sand about the packings 24 and 43 is avoided so thatthere is no sand locking of these n1em bers between the carrying nipplesand the casing by reason of the provision of the holes 25 and 44 and themilled out passageways 26 so that instead of having a quiet zone atthese locations, water is iiowing in and out to avoid the collection ofthe foreign material, particu larly sand in those zones.

Holes 29 in the pipe 28 and the tube holes 36, par' ticularly adjacentthe head 34, avoid damaging concussion by releasing flow slightlythrough the holes, as the upper cage 12 is reciprocated with itsappended parts.

Thus by following this operation, the water may be cleared shortly afterthe working loose of the clay and sand and then lifting it out of thewell. When the' well n is cleared and properly developed, then thedevice may be lifted therefrom, and the two cages 38 and 12 closecoupled by sliding the tube 33 inwardly of the pipe Z8 and inserting thebolt 35 again as above described so that the tool may then be carriedabout with less difliculty by reason of its lessened overall length.

Reference has been made above to the collar 45 being slidably carried onthe lower end of the nipple 40 within the limits of the underside of thepacking ring 43 and the outwardly extending portion 47. By reasonof thisconstruction, the entire Weight of all of the construction carried aboveby the lower valve cage 38 may rest directly upon the packing ring `43when the lower collar 48 is seated and stopped by any element in itspath, such as the screen 11. -In this manner, the packing ring 43 isspread laterally into a full sealing contact so that there be no passageof water therepast externally of the nipple 40. By removing the weight,that is by pulling upwardly on the member 14, the load is taken off'ofthe packing ring 43, and due to its elasticity, it will of course returnto its normal contracted state and thus be easily removed from withinthe casing 10. The packing 43 will come into sufficient compressivesliding contact with the inside of the casing to permit the sloshing upand down of the water within the casing during the surging action.

Therefore while I have herein shown and described one particular form ofmy invention, it is obvious that structural changes may be employedwithout departing from the spirit of the invention, and I therefore donot desire to be limited to that precise form beyond the limitationswhich may be imposed by the following claims.

lI claim:

1. A well developing device for use within a casing comprising an uppervalve cage reciprocable within the casing, said cage having a fluidpassage extending lengthwise therethrough and communicating with anopening into the casing; a packing ring carried bythe cage slidablealong the casing; an outer sleeve pipe of less diameter than theinternal diameter of the casing and suspended from the valve cage; saidpipe communicating with said uid passage and being perforated adjacentsaid cage; an

inner tube perforated and reciprocable within and extending by a lowerend from said pipe; said pipe and tube having flow clearancetherebetween; an abutment at the lower end of said pipe; an abutmentextending from the upper end of said tube in the path of the pipeabutment arresting travel of the tube from the pipe; a lower valve cagecarried by said inner tube end, said lower cage having a uid passageextending lengthwise therethrough communicating with said inner tube andcommunicating with an opening into the casing; a packing ring carried bysaid lower valve cage; a collar carried by 'and longitudinallyreciprocable of said lower cage; said collar supporting vertically saidlower cage and communicating with said fluid passage therethrough; saidlower cage having a shoulder under which its said packing ring ispositioned and the weight of said two cages and said pipe and tube beingsupported by said shoulder riding on said lower packing ring in turnsupported by said collar when held against downward travel; and a valvedisc in each of said cages, the disc in the upper cage normally closingoff communication between its said iluid passage and said pipe, and thedisc in the lower cage normally closing olf communication between itssaid uid passage and through said collar, both discs being lifted byfluid pressure thereagainst upon downward travel of the cages.

2. The structure of claim 1 in which holes in both said pipe and tubemay be transversely aligned `and a bolt is extended through both thepipe and the tube aligned holes to retain the pipe and tube againsttravel one in relation to the other.

3. The structure of claim 1 in which said upper cage also has a shoulderunder which the upper cage packing ring is retained; said cages havingwashing out passageways over both of said rings from the casing sidesthereof into the cages below said discs.

References Cited in the ile of this patent UNITED STATES PATENTS

